2009 Hurricane Season

2009 Hurricane Season: Storms in Teacup, or Nasty Surprises?

What would the 2009 Hurricane Season be like, if all else stayed the same?

[The Atlantic Basin Hurricane Season officially starts on June 1, and lasts through November 30.]

Here’s what Colorado State University experts, Philip J. Klotzbach and William M. Gray believe:

The following excerpts are from:

EXTENDED RANGE FORECAST OF ATLANTIC SEASONAL HURRICANE ACTIVITY AND U.S. LANDFALL STRIKE PROBABILITY FOR 2009

(As of 7 April 2009) We foresee average activity for the 2009 Atlantic hurricane season. We have decreased our seasonal forecast from our initial early December prediction. We anticipate an average probability of United States major hurricane landfall.

Atlantic Basin Seasonal Hurricane Forecast for 2009 – Courtesy of Colorado State University

PROBABILITIES FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE LANDFALL ON EACH OF THE FOLLOWING COASTAL AREAS:

1) Entire U.S. coastline – 54% (average for last century is 52%)
2) U.S. East Coast Including Peninsula Florida – 32% (average for last century is 31%)
3) Gulf Coast from the Florida Panhandle westward to Brownsville – 31% (average for last century is 30%)
4) Average major hurricane landfall risk in the Caribbean

CSU report says:

• The 2009 Atlantic hurricane season will have about as much activity as the average 1950-2000 season.

Expect about:

• 6 hurricanes (average is 5.9),
• 12 named storms (average is 9.6),
• 55 named storm days (average is 49.1),
• 25 hurricane days (average is 24.5),
• 2 intense (Category 3-4-5) hurricanes (average is 2.3) and
• 5 intense hurricane days (average is 5.0).

The probability of U.S. major hurricane landfall is estimated to be about 105 percent of the long-period average. We expect Atlantic basin Net Tropical Cyclone (NTC) activity in 2009 to be approximately 105 percent of the long-term average. We have decreased our seasonal forecast from early December.

This forecast is based on an extended-range early April statistical prediction scheme that utilizes 58 years of past data. Analog predictors are also utilized. The influence of El Niño conditions is implicit in these predictor fields, and therefore we do not utilize a specific ENSO forecast as a predictor.

We expect current weak La Niña conditions to transition to neutral and perhaps weak El Niño conditions by this year’s hurricane season. If El Niño conditions develop for this year’s hurricane season, it would tend to increase levels of vertical wind shear and decrease levels of Atlantic hurricane activity. Another reason for our forecast reduction is due to anomalous cooling of sea surface temperatures in the tropical Atlantic. Cooler waters are associated with dynamic and thermodynamic factors that are less conducive for an active Atlantic hurricane season. [From CSU]

What do others think?

Meanwhile, AccuWeather.com, a private forecaster run by Joe Bastarde, has cut its forecast for this year’s Atlantic Hurricane season to 10 from 12 it predicted in March, this year.

AccuWeather says 6 of the storms will be hurricanes this year [it predicted 8 in March,] with only 2 of them rising to category 3 or stronger on the  Saffir-Simpson scale. [See also FEWW Hurricane Scale.]

AccuWeather says only two hurricanes, one of them category 3 or stronger, will strike the U.S. coastline.

“Anywhere along the U.S. coast is susceptible to an impact, but the Texas coast early in the season and East Coast from Carolinas northward during the heart of the season are areas that have us worried,” Bastarde  said.

In another interesting statement, AccuWeather’s Bastarde predicted that intense rapidly developing  “pop-up” hurricanes may plague the Gulf of Mexico during the 2009 Atlantic Hurricane season. This prediction is bound to haunt the imagination of the oil industry, and keep the hard disks on AccuWeather servers spinning till smoke comes out.

“We’re not going to see the long-term classic storms crossing the Atlantic and the Caribbean, like we saw in 2008,” Bastarde said. “We may see rapidly-developing storms like (hurricanes) Humberto and Alicia.”

In 2008 16 named tropical storms were formed over the Atlantic Basin, which included 8 hurricanes (5 of them were rated as major).

About 50 percent of the 2008 tropical storms affected the U.S. coastline, including four hurricanes.

FEWW will revise and update its previous long-range Atlantic Basin Hurricane forecast  for the 2009 season soon.

Related Links:

• Ike Update 9/12: Who Rubbed the Oil Lamp?
• Norbert Strengthens to a Cat 4 Hurricane
• 2008 second worst year for disaster losses
• Six Costliest US Atlantic Hurricanes to Date
• Hurricane Ike, TS Hannah, TS Josephine – Update 9-5